Device for ultrasonically cleaning phonographic records



R. W. HENES Sept. 17, 1968 DEVICE FOR ULTRASONICALLY CLEANING PHONOGRAPHIC RECORDS Filed Nov. 28, 1966 3,401,708 DEVICE FOR ULTRASONICALLY CLEANING PHONOGRAPHIC RECORDS Richard W. Henes, 5901 E. Calle Del Sud, Phoenix, Ariz. 85018 Filed Nov. 28, 1966, Ser. No. 597,293 7 Claims. (Cl. 134-149) This invention relates to cleaning devices and more particularly to a device for ultrasonically cleaning phonographic records.

Even though modern day records are pressed from the finest pure vinyl materials and the sound impressions recorded thereon by the latest, most highly developed sound equipment, surface noises caused by dust attracted by static electricity destroy the clarity, musical range and natural balance of the recordings. Dust and dirt filled grooves cause undue record wear resulting in a loss of the high fidelity sounds recorded thereon.

v.. .He1gt g fore cleaningmists, among other things, have been provided"forkeepingrcordslclean andiiust free, but these cleaning products require wiping the micro-groovedrecord surfaces with a soft brush or cloth. This action results in a premature wearing of the record surface. As is evident from this form of cleaning the grooves in the records are worn or damaged from the abrasive cleaning action and the dirt is forced deeper into the grooves. Even though surface noises are reduced the original tonal brilliance of the recordings are materially lessened.

In accordance with the invention disclosed a new and improved device is provided for ultrasonically cleaning records. Surface noises and the resulting groove wear caused by dust particles are substantially reduced or eliminated. The tonal brilliance of the record is retained and its life greatly increased.

It is, therefore, one object of this invention to provide a new and improved ultrasonic cleaning device for phonographic records.

Another object of this invention is to provide a new and improved housing containing a cleaning solution for axially mounting a phonographic record.

A further object of this invention is to provide a new and improved apparatus for immersing at least a part of a phonographic record in a cleaning solution and then generating an ultrasonic field for removing contamination from the surface of the record.

A still further object of this invention is to provide a new and improved cleaning tank employing a transducer mounted on its side for automatically cleaning a phonographic record placed therein.

Other objects and advantages of this invention will become apparent from the following description when read in connection with the acompanying drawing, in which:

FIG. 1 is a perspective view partly broken away of an ultrasonic phonographic record cleaning device and embodying the invention;

FIG. 2 is an enlarged cross sectional view of the structure shown in FIG. 1 taken along the line 22; and

FIG. 3 is an enlarged cross sectional view partly broken away of the structure shown in FIG. 2.

Referring more particularly to the drawing by characters of reference, FIGS. 1-3 disclose a device for ultrasonically cleaning phonographic records. Device 10 comprises a base 11 of any suitable geometrical configoration having mounted on it a tank 12 containing a suitable cleaning material such as for example a water-detergent or trichloroethylene solution 13. The tank may A Patent 0 3,401,708 Patented Sept. 17, 1968 larger than the thickness of the record to be cleaned,

be of a substantially semi-cylindrical configuration having thereby providing '-a"space for an adequate amount of cleaning solution on each sideof the record. For practical installations the tank may be up to twenty-five times the thickness of the records to be cleaned.

Record 16 shown in FIGS 1-3 is axially mounted shaft 17 within tank 12 and arranged between and parallel to its end walls 14 and 15. A pair of ears 18 and 19 fixedly secured to a flange 20 formed around the diameter of the semi-circular shaped configuration forming tank 12 provides spaced bearing mountings for shaft 17. The flange 20 in addition to strengthening the side walls of the tank also supports the tank within an opening 21 in base 11.

As shown in the drawing the record is mounted substantially on the rectangular coordinate axis lying in the plane formed by the semi-cylindrical configuration. If so desired, the tank 12 may be provided with suitable supporting leg members in lieu of base 11.

Shaft 17 is arranged to snugly fit within the spindle opening in record 16 so as to cause the record arranged 'tioned between the end walls torotate upon rotation of th'eEHeTftTsuitable-hQadl shaft and record during a cleaning operation. If desired, the record may be loosely mounted on shaft 17 and rotated by merely spinning the record by hand.

Fixedly attached to the outside of tank 12 is a transducer 23 for generating vibratory ultrasonic waves. There are several possible means of producing ultrasonic waves, the most common of which is the crystal transducer where crystal refers to a number of natural and synthetic materials which exhibit piezoelectric or similar phenomena effects. The piezoelectric effect is defined as a change in the crystal dimensions when an electric charge is applied to at least one of the crystal faces.

Quartz crystals have been used for generating ultrasonic vibrations in solids and liquids and have been widely used for sending and receiving wave energy at low power conditions. Frequencies produced by quartz type transducers cover a range of a few hundred kilocycles to about 25 megacy-cles when vibrating in a fundamental mode and can extend to a much higher frequency when operating at a harmonic frequency.

Besides quartz, Rochelle salt may be used in the generation of ultrasonic waves in liquid, especially in the low-frequency ranges. At the present time barium titanate or lead zirconate titanate and lithium sulfate have been used in crystal form for developing ultrasonic waves.

When an alternating current is applied to the crystal at a high frequency and the crystal is properly designed to oscillate at that frequency, the faces of the crystal will move with respect to each other. If one face of the crystal is pressed against the surface of a medium such as the wall of a tank, ultrasonic waves will be produced, enter the medium, and then travel through that medium providing the medium is able to support the propagation of the ultrasonic wave. It is not necessary for a crystal to vibrate or oscillate at its resonant frequency. Crystals can be driven at any frequency, however, the amplitude of crystal oscillation is so much greater at resonance that crystals are rarely used at any other frequency. The crystal will vibrate in different directions depending on the way it is cut and the change in its dimensions is proportional to the electrical force applied thereto. For more detail analysis of the proprieties of crystals for ultrasonic use reference is made to the text Ultrasonics by Benson Carlin published in 1960 by the McGraw-Hill Book Company, Inc.

As shown in FIG. 1 transducer 23 employing a suitable crystal is connected to a source of alternating curf '-formed..at, one end of shaft 17 for ease in grasping and rotating t e rent supply 24 having a frequency of 20,000 to one million cycles per second. The alternatingcurrent supply may comprise any conventional oscillator-poweramplifier arrangement used for ultrasonic cleaning applications.

The transducer as shown in the drawing isco'up'led to the side of tank 12. Although it is shown as being coupled to the outside of the tank it may function equally as Well if dropped inside to the bottom of the tank. .'Further, it may be mounted in an aperture in the sidewall of the tank, if so desired.

When record 16, which may be formed of vinyl or any other suitable material, is mounted on shaft 17 it is partially immersed-in a cleaning solution with its grooves filled with the cleaning material. Upon the application of a high frequency alternating current to transducer 23, it will vibrate at a high frequency. Ultrasonic waves will be generated which will be conducted through the sidewall of the tank into the cleaning solution. If the transducer is mounted in the tank or in a hole in the tank wall, the ultrasonic wave will be applied directly to the cleaning solution. Ultrasonic waves have been found to cause pressures so large that the resulting mechanical stresses may be as great as 15,000 times the hydrostatic pressure of the solution. The acceleration of the crystal driving such a bath is extremely great and may reach 20,000 km./sec. but the motion associated with such action is extremely small (a very small fraction of 1 mm.). This velocity will be generated by the crystal in a fraction of a microsecond.

This action of the transducer results in a cleaning action on the surface of the record and particularly in its grooves when the record is immersed in the solution and rotated past the transducer. The cleaning action is believed to be due to a combination of cavitation and acceleration of the cleaning fluid. Cavitation is defined as the formation and collapse of cavities in liquids, either gas or vapor filled.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

It is claimed and desired to secure by Letters Patent:

1. A device for ultrasonically cleaning micro-grooved phonographic record surfaces comprising in combination 4 a tank for housing a cleaning solution, said tank comprising a pair of end walls having their plane surfaces substantially vertically arranged and spaced apart a distance up to twenty-five times the thickness of the record to be cleaned, means for rotatably mounting a record in i said tank between and substantially parallel to said end walls, and a transducer supported by said tank for generating vibratory waves when connected to a suitable source of power, said transducer being coupled to one of said end .walls so as to radiate vibratory waves substantially directly into the micro-grooved surfaces of the record as the record is rotated in said tank.

2. The combination as defined in claim 1 wherein said transducer generates ultrasonic vibratory waves.

3. The combination as iefined in claim 1 wherein said transducer generates ultrasonic waves having a frequency between 20,000 and one million cycles per second.

4. The combination as defined in claim 1 wherein said end walls of said tank are of a semi-circular configuration.

5. The combination as defined in claim 1 wherein said tank is of a semi-cylindrical configuration and said means for rotatably mounting the record is mounted substantially on the rectangular coordinate axis lying in the plane formed by the semi-cylindrical configuration.

6. The combination as defined in claim 5 wherein said means for mounting the record comprises a shaft for extending through the central hole in the record.

7. The combination as defined in claim 1 wherein said tank is a semi-cylindrical configuration and said means for rotatably mounting the record is located and mounted substantially on the common axis of the two semi-circular side walls of said tank.

References Cited UNITED STATES PATENTS 2,925,063 2/1960 Mondry 134 157 XR 2,938,732 5/1960 Mantell 134 149 XR 3,345,075 10/1967 Phillipson et al. 274-47 OTHER REFERENCES IBM Technical Disclosure Bulletin, Method of Cleaning Magnetic Tape, by R. S. Haines, Vol. 1, No. 6, April ROBERT L. BLEUTGE, Primary Examiner. 

1. A DEVICE FOR ULTRASONICALLY CLEANING MICRO-GROOVED PHONOGRAPHIC RECORD SURFACES COMPRISING IN COMBINATION A TANK FOR HOUSING A CLEANING SOLUTION, SAID TANK COMPRISING A PAIR OF END WALLS HAVING THEIR PLANE SURFACES SUBSTANTIALLY VERTICALLY ARRANGED AND SPACED APART A DISTANCE UP TO TWENTY-FIVE TIMES THE THICKNESS OF THE RECORD TO BE CLEANED, MEANS FOR ROTATABLY MOUNTING A RECORD IN SAID TANK BETWEEN AND SUBSTANTIALLY PARALLEL TO SAID END WALLS, AND A TRANSDUCER SUPPORTED BY SAID TANK FOR GENERATING VIBRATORY WAVES WHEN CONNECTED TO A SUITABLE SOURCE OF POWER, SAID TRANSDUCER BEING COUPLED TO ONE OF SAID END WALLS SO AS TO RADIATE VIRBATORY WAVES SUBSTANTIALLY DIRECTLY INTO THE MICRO-GROOVED SURFACES OF THE RECORD AS THE RECORD IS ROTATED IN SAID TANK. 